Japanese Coast Guard vessels have fired water cannons at a Taiwanese boat to keep a group of activists from landing on East China Sea islands at the centre of a dispute that's strained ties between Japan and China.

The Taiwanese boat left the area along with four Taiwanese coast guard vessels that had accompanied it, the Japanese Coast Guard said in a faxed statement.

Three Chinese Marine Surveillance vessels were also circling the islands just outside Japanese-administered waters, according to the statement.

China has demanded that Japan withdraw its September purchase of the islands, elevating tensions between Asia's biggest economies that has damaged a US$340 billion trade relationship and prolonged Japan's recession.

The United States has repeatedly said the chain, also claimed by Taiwan, falls under a mutual defence treaty with Japan while saying it takes no position on sovereignty.

Taiwan's trip was aimed at safeguarding sovereignty and protecting its citizens, the Coast Guard Administration said in a statement on its website.

The group aimed to put a statue of the sea goddess Matsu on the islands, Taipei-based Central News Agency reported.

Japan last shot water cannons in September to drive off about 50 Taiwanese fishing boats and patrol vessels from the islands, known as Diaoyu in Chinese and Senkaku in Japanese.

The dispute has escalated in the past month, with both China and Japan dispatching fighter jets to monitor each other's movements in the area.

Japanese Coast Guard vessels had earlier tried to block the Taiwanese ships 28 nautical miles from the islands, Taiwan's Central News Agency said.

China this week criticised US Secretary of State Hillary Clinton for saying the US opposes any effort to disrupt Japan's administration of the islands.

Her talks in Washington with Japanese Foreign Minister Fumio Kishida were the highest level meetings between the two allies since Prime Minister Shinzo Abe took office last month.

He pledged to boost defence spending in response to China's claims to the area, which are rich in oil, natural gas and fish.

Abe made an overture to China this week by having coalition New Komeito Party leader Natsuo Yamaguchi carry a personal letter to Beijing from him to Communist Party General Secretary Xi Jinping.

In an editorial today, the Chinese state-run Global Times newspaper said it was doubtful that "the secret whispers brought by Yamaguchi are valuable."